The present disclosure relates to the field of microvalves, specifically to a microvalve that can be repeatedly opened and sealed.
A typical structure for a Micro Electro Mechanical System (MEMS) microvalve includes an orifice and a moveable plate that can be actuated to press against the orifice. When the plate does not press against the orifice, fluid can flow through the orifice and therefore through the valve. When the plate is pressed against the orifice, fluid flow through the valve is restricted. Although the flow is restricted, this type of microvalve does not seal fully, and some flow continues through the orifice. The ratio of open flow rate to closed flow rate for valves that have a flow rate when open of at least 1 standard centimeter cubed per minute (sccm) is typically up to about 10,000. This does not provide adequate sealing for long periods of time.
There are valves that provide a substantially leak-free seal; however, the seal of these valves are permanent. A closed valve, which is sealed by solidifying a sealing material, may be opened by melting the sealing material. However, when the sealing material melts, the sealing material drains away, not allowing the valve to be reused without adding more sealing material.
In many of the applications, it may be desirable to use a valve that can be repeatedly opened and closed and can provide a substantially leak-free seal in the closed state and a relatively high flow rate in the open state.